Method:Combine the sugar, butter, cream cheese, salt, almond and vanilla extracts and the egg yolk in a large bowl. Beat until smooth.

Stir in flour until well combined.

Chill the dough overnight. The next day, preheat the oven to 190°C / 375°F / Gas mark 5. On a lightly floured surface, roll out the dough 1/3 at a time until you have the desired thickness, chill the remaining dough until ready to use.

Using a Shamrock shaped cookie cutter, cut your shapes. Place each cookie about 2 cm apart on a baking tray lined with greaseproof paper. Leave the cookies plain for frosting, or brush with a slightly beaten egg white and sprinkle with candy sprinkles or coloured sugar.

Bake for 7 to 10 minutes or until light and golden brown. Repeat the process with the chilled dough until you have used all of it between batches.